I planted pole beans in the spring. They are very healthy looking plants but no flowering = no beans. What’s my problem, please? If I may, I also planted one thornless blackberry plant last year and started new plants by burying some of the vines. Great tasting blackberries, currently the plant is about 6 ft. tall and falling over. Should I prune the plant back or wait till fall and restart additional plants?
The Gardener’s Answer
Hello, Tom in Kentucky: There are a few possibilities why your beans are not flowering, the most common reason being not enough sunlight. Pole beans require a minimum of six hours of direct light. The plant itself may be happy in part shade but you will not get to enjoy many beans. Another possibility is too much nitrogen fertilizer. Plant food that is high in nitrogen encourages foliage growth but actually discourages flowering. One last thought is when air temperatures reach 90 degrees F or above pod set is typically decreased, and we have had a lot of those days this summer. Depending on when you got your seeds or starts in the ground and how many days the variety you planted takes to harvest, it may not be time for your vine to flower yet. Pole beans bloom mid to late summer depending on a few different variables. As for your blackberries, it depends on what kind you are growing. From the height you mentioned I assume you are growing semi-erect and these cultivars should be pruned during the winter while they are dormant. They should be cut back where the canes start bending over. They can also be pinched back during the summer months if at any time the canes have put on more than one foot of new growth. This will encourage larger fruit. So really the decision is yours, if you wish to propagate more plants than go ahead and do so, but if you have enough and just want to maintain the ones you have you can prune them this winter. For more detailed information on growing/pruning blackberries, visit www.ca.uky.edu/agc/pubs/ho/ho15/ho15.pdf.